Abrading machine



July 30, 1946. E. c. MURDOCK 2,404,917

ABRADING MACHINE Filed July 2'7, l 945 4 Sheets-Sheet l July 30, 1946. a c. MURDOCK ABRADING MACHINE Filed July 27, 1945 4 Sheets-Sheet 2 mm mg July 30, 1946. E. c. MURDOCK I ABRADING MACHINE Filed July 27, 1945 4 SheetsSheet 3 July 30, 1946. E. c. MURDOCK ABRADING MACHINE Filed July 27, 1945 4 Sheet 4 viva Q Patented July 30,1946

UNITED STATES PATENT OFFICE 4 Claims.

This invention relates to a machine for abrading or sanding or polishing objects such as the backs and seat slats of a wooden chair. These seat slats are usually not only curved but sometimes provided with reverse curves and it is quite a manual operation to hold these pieces of wood against an abrading wheel for removing the roughness therefrom and dressing the same so that they are ready for use in the manufacture of a chair.

It is an object of this invention to provide a machine whereby the slats can be fed through the machine and instead of having abrading wheels, providing elongated endless belt covered with abrading material, whereby the slats after being inserted into the machine will be automatically fed therethrough and both sides of the slats will be dressed and polished and all roughness removed therefrom. Also, instead of having a conventional abrading wheel, by having an elongated belt, a much greater length of time will occur between the times when a new abrading surface must be provided.

It is another object of this invention to provide an abrading machine having a pair of rollers on each of which is disposed an endless abrading belt with spring means for pressing the rollers towards each other and feeding rollers disposed above and below the abrading rollers for feeding the slats through the machine.

Some of the objects of the invention having been stated, other objects will appear as the description proceeds when taken in connection with the accompanying drawings in which:

Figure 1 is a side elevation of the machine;

Figure 2 is a top plan view of the machine;

Figure 3 is a vertical sectional view on an enlarged scale and taken along the line 3-3 in Figure 2;

Figure 4 is a vertical sectional view taken along the line 44 in Figure 3;

Figure 5 is an enlarged side elevation of the central portion of Figure 1;

Figure 6 shows a form of slat or chair back which can be operated upon by this machine;

Figure 7 shows a form of slat having its endss reversely curved and which is adapted to be used in the manufacture of a chair seat.

Referring more specifically to the drawings,

numeral l0 indicates uprights and between these and in spaced relation, by means of suitable straps l1 and I8 and cross straps I9, 20, 2|, and 22.

At one end of the machine there is provided an electric motor 25 having a small V-pulley 21 having V-belts 26 thereon. These V-belts 26 are also mounted on a V-pulley 28 disposed on a shaft 29 which is mounted in a suitable bearing 30 slidably mounted between the upper and lower side angle bars II and I2 on one side, and I3 and I4 on the other side.

There is a suitable bridging member 3| disposed between these angle bars, and an adjusting screw 32 is mounted in these vertical bridging bars 3 l, by means of which the position of the bearing 3| can be adjusted relative to the upper and lower angle bars II and I2, or l3 and I4. This shaft 29 has a smaller V-pulley :34 aflixed on its other end on which a V-belt 35 is mounted, which V-belt is also mounted on a larger V-pulley 36 fixed on a transverse shaft 31 mounted in suitable bearings disposed between the upper and lower angle bars on each side of the frame; these bearings are held in position by means of suitable bolts 38. This shaft 31 has a sprocket wheel 40 on its other end on which is mounted a sprocket chain 4| which is also mounted on a sprocket wheel 42 on a feed shaft extension 43, the feed shaft 43 being corrugated. This feed shaft 43 is slidably mounted in slots 44 in channel bars 45 which are mounted for swinging movement of the upper end of links 46 and 4! which are pivoted at their ends in the upper channel bar II or I 3 as the case may be. This channel bar 45 is held in swinging resilient position by means of compression springs 59 and 5| pressing against the ends of the channel bar 45 and being anchored against angle irons 52 and '53 secured on the upper surface of the upper channel bars II and 63. This shaft 43 at each side is mounted in a slidably mounted bearing 54 clearly visible in Figures 3 and 4. The bearing 54 is also pressed towards the right in Figures 3 and 5 by means of a compression spring 55 being disposed between the closed end of the member 45 and the bearing 54.

On the lower surface of the lower angle bars l2 and I4, respectively, a structure similar to that described is also present. It comprises a pair of links and GI projecting downwardly, the lower ends of which are pivoted to a channel bar 62 identical in all respects to channel bar 45. This channel bar 62 has slidably mounted therein a bearing 63 in which a second feed roller 64 is mounted, there being a member 62 at each side of the frame and a bearing 63 at each side of the frame, This bearing 63 is resiliently pressed to the right in Figures 3 and by means of a compression spring 65 being disposed between the bearings 63 and the closed end of the channel bar 62. Also a spring 66 presses against the left hand end of the member 62 and tends to swing it to the right in Figures 3 and 5.

The left hand end of this compression spring 66 is anchored by means of an angle bar 61 at the left end and an angle bar 68 at the right end while a compression spring 69 is at the right hand end and counteracts the force of compression spring 63 to thus balance the member 52 at all times.

The lower roller 64 has a sprocket wheel H thereon. The sprocket chain 4! passes downwardly and engages this sprocket wheel ll before returning to the sprocket wheel 4%. This causes both of the rollers 43 and 64 to rotate in a clockwise direction in Figures 3 and 5. 7

At the other end of the machine there is an electric motor 75 having a small V-pulley E5 on its motor shaft and on which is mounted a pair of V-belts TI which are mounted on a V-pulley I8 affixed on a transverse shaft I9 mounted in suitable bearings 80 disposed between the horizontal angles H and I2, and I3 and I4, respectively.

A vertical bridging bar BI is provided between the upper and lower angles on each side and a set screw 82 is threadably mounted therein for engaging the bearings 80 for adjusting the posi tion of the bearings relative to the angle bars II and I2, and I3 and I4, respectively. The shaft 19 has mounted on the other end thereof V- pulley 83 on which a V-belt 84 is mounted which is also mounted on a /-pulley 85 secured on one end of a transverse shaft 86 and on the other end of this shaft 86 is mounted a sprocket wheel 8?. The shaft 86 is mounted in suitable bearings 88 disposed between the upper and lower angle bars H and I2, and I3 and Id, respectively. The sprocket wheel 8'! has mounted thereon a sprocket chain 89 which is also mounted on a sprocket Wheel 90 fixed 0n the end of corrugated feed shaft 9! which extends through the machine and is mounted in bearings 92 near each end thereof. These bearings 92 are slidably mounted in the channel bars 45 at each side of the machine and they are pressed towards the other bearing 54 therein by means of a compression spring 93 being anchored between the closed ends of the bars 45 and the bearings 92.

Also mounted in each of the lower channel members 52 are bearings 95 in which the ends of lower feed roller 96 are mounted. The lower feed roller 56 has a sprocket wheel 91 fixed on the end thereof and sprocket chain 89 after passing over sprocket wheel 96 passes over sprocket wheel 91 before returning to sprocket wheel Bl.

The above-described arrangement allows the upper and lower sets of feed rollers to run in opposite directions, that is, with their top portions running towards each other so that they tend to feed the work pieces through the machine by rotation of the same. The lower member 62 in which bearing 63 and 95 are mounted has pivoted on these bearings a pair of members 518 and 98a having sloping surfaces. These members 98 and 98a rest on the feed rollers 64 and 96, respectively, and tend to guide the lower end of a work piece 99 through the lower feed rollers.

Mounted on the shaft 29 is a pulley Iilil which has a belt I III of abrasive material mounted thereon and this belt is also mounted on a rubber roller I03 mounted at its ends in suitable bearings HM sliding between the upper and lower angle bars II and I2, and I3 and I4, respectively.

Fixed on the upper angle bars II and I3 is a pair of drive members I and IE6 which guides the work piece 99 between the two feed rollers. The two rubber rollers may be pneumatically inflated rollers, but they are shown as plain rubber rollers in the drawings. The roller I83 nor mally tends t move to the left in Figures 3 and 5 due to the force of a compression spring I01 which is loosely mounted around a rod I08 which is fixed in the bearing which has its other end slidably mounted in a vertically disposed bridging gap I59. On the shaft I9 there is fixed another pulley III on which other another abrasive belt H is mounted, this belt bein mounted also on a rubber roller II 3 the ends of the roller bein suitably mounted in bearings H4 at each end thereof slidably disposed between upper and lower angles II and I2, and I3 and I4, respectively, and is forced to the right in Figures 3 and 5 by means of a compression spring II5 surrounding a rod H6 one end of which is fixed in the bearing H4 and the other end slidably mounted in a vertically disposed bridging bar I IT.

The belt I-JI is tensioned by means of idler roller I26 being mounted between the free ends of arms I2I which are pivoted at their ends to vertical bridging bars I 22 secured between the upper and lower angle bars II and I2, and I3 and I l, respectively. Th belt III is also tensioned by means of a roller l25 mounted between the free ends of links I26 whose other ends are pivotally secured to upright bridgin bars I5 as previously described.

In the drawings and specification there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. An abrading machine comprising a frame, a pair of rollers mounted in the frame, spring means for pressing the two rollers toward each other, a pulley mounted in each end of the frame, an endless abrasive covered belt mounted on the rollers and their associated pulleys, means for imparting rotation to the pulleys for imparting rotation to the belts, the proximate surfaces of the rollers moving in the same direction, means on each side of the rollers for feeding a workpiece between the rollers in a direction opposite to the direction of rotation of the proximate surface of the rollers, the means for feeding the workpiece between the rollers comprising a pivoted frame disposed on each of the opposite sides of the rollers, resilient mean for restraining each pivoted frame against endwise movement in both directions, each frame having a pair of feed rollers mounted therein, means for driving the proximate surfaces of the feed rollers in the same direction to feed the workpiece between the rollers having the abrasive belts thereon, and guiding means disposed between the rollers having the abrasive belts thereon.

2. In an abrading machine for abrading the surfaces of a wooden workpiece such as chair slats and the like, a main frame having a pair of resilient rollers mounted approximately midway of the main frame, a pulley mounted near each end of the main frame, a pair of endless abrasive belts, th'ere being a belt mounted on each feed roller and a pulley near the end of the main frame, means for driving the belts and. the rollers so that the proximate surfaces of the rollers move in the same direction, means for resiliently pressing the two rollers toward each other, a swinging frame member mounted on each side of the main frame opposite the rollers, resilient means for permitting endwise movement of the swingin frame members relative to the main frame but normally tending to hold the frame members in a given position, a pair of feed rollers mounted in each of the frame members, there being a pair on each side of the rollers on which the abrasive belts are mounted, means for driving the abrasive belts and for driving the feed rollers so that the feed rollers have their proximate surfaces moving in the same direction and in an opposed direction to the direction of rotation of the proximate surfaces of the rollers on which the abrasive belts are mounted, and means for guiding the end of the workpiece after the piece goes through one set of feed rollers and between the abrasive belts into a position between the next set of feed rollers.

3. An abrading machine comprising a pair of endless abrasive belts, a pair of rotatable means for supporting the belts for rotation, means for urging the proximate ends of the belts towards each other so that a workpiece can be passed therebetween to finish the same, a pair of resiliently mounted feed rollers disposed on each side of the rotatable means on which the proximate ends of the abrasive belts are mounted for feeding a workpiece between the proximate ends of the abrasive belts and means for driving the feed rollers so that their proximate surfaces move in the same direction and for also driving the abrasive belts so that their proximate ends rotate in the same direction but in a direction opposite to the direction of rotation of the proximate surfaces of the feed rollers.

4. An abrading machine comprising a pair of resilient rollers, a pair of power driven pulleys rotatably mounted remotely from each roller, a pair of endless belts having an abrasive covering, there being a belt mounted on each roller and its remotely associated pulley, a swinging resiliently mounted frame disposed on each of the opposite sides of the rollers and each frame having a pair of driven feed rollers for pushing and pullin a workpiece between the resilient rollers, and means for driving the feed rollers at a low rate of speed and for driving the rollers carrying the belts at a faster rate of speed.

ELMER CONDA MURDOCK. 

